login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A085062
a(n) = A085060(n)/9 - 1/3.
5
0, 1, 1, 4, 2, 4, 3, 13, 4, 7, 5, 13, 6, 10, 7, 40, 8, 13, 9, 22, 10, 16, 11, 40, 12, 19, 13, 31, 14, 22, 15, 121, 16, 25, 17, 40, 18, 28, 19, 67, 20, 31, 21, 49, 22, 34, 23, 121, 24, 37, 25, 58, 26, 40, 27, 94, 28, 43, 29, 67, 30, 46, 31, 364, 32, 49, 33, 76, 34, 52, 35, 121, 36, 55
OFFSET
0,4
COMMENTS
Interlacing of A001477 and A085060 / 3. - Ruud H.G. van Tol, Aug 30 2024
LINKS
J. C. Lagarias and N. J. A. Sloane, Approximate squaring (pdf, ps), Experimental Math., 13 (2004), 113-128.
FORMULA
a(n) mod 2 = A292077(n+1). - Alois P. Heinz, Jul 01 2023
a(2*n) = n; a(2*n+1) = 3 * a(n) + 1. - Ruud H.G. van Tol, Aug 31 2024
MAPLE
a:= n-> `if`(n::odd, a((3*n+1)/2), n/2):
seq(a(n), n=0..100); # Alois P. Heinz, Jul 01 2023
PROG
(PARI) a(n) = ((3/2)^valuation(n++, 2)*n-1)/2; \\ Ruud H.G. van Tol, Aug 30 2024
CROSSREFS
Bisection gives: A001477 (even part).
Sequence in context: A010316 A083954 A038702 * A053051 A075234 A232715
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Aug 11 2003
STATUS
approved